This proposal describes a population-based cohort aimed at determining the prevalence and incidence of cardiovascular disease morbidity and mortality in people with Type 1 diabetes of long-duration. For this epidemiologic study, subjects include all insulin-taking persons who: (1) were less than 30 years of age at the time of their diagnosis, (2) had received primary medical care in an 11-county area of south-central Wisconsin, and (3) were first identified in 1979-80. Standardized protocols for examinations and interviews have been employed during the baseline, 4-, 10-, and 14-year follow up examinations. Refusal rates have been low. The mean age of the cohort and the long duration of diabetes provide an opportunity to document the prevalence and incidence of coronary heart disease, myocardial infarction, angina, congestive heart failure, stroke, transient ischemic attacks, peripheral vascular disease, and cardiovascular disease mortality in a large population-based group of persons with Type 1 diabetes. Retinal photographs of each study participant were taken at the baseline examination. This will permit us to test the predictive ability of focal and generalized retinal arteriolar narrowing and arterio-venous cross changes (i.e. A/V nicking) for subsequent macrovascular events controlling for other risk factors. These factors include blood pressure, cigarette smoking, serum lipids, body mass index, duration of diabetes, and glycemia. We plan to reexamine this cohort to obtain ECGs, blood lipid fractions not previously measured, and fibrinogen, as well as upper and lower extremity blood pressures, urine specimens, and medical records. This will provide information about silent about silent infarctions and other cardiographic abnormalities as well as previously doctor-diagnosed macrovascular events in long-term survivors of Type 1 diabetes. Study examinations will be performed in a mobile van. Participants will provide two urine specimens for determination of urinary albumin excretion. Fasting blood will be obtained for determination of glycosylated hemoglobin Alc, blood sugar, serum cholesterol, triglycerides, HDL- cholesterol, LDL-cholesterol, VDL-cholesterol, LDL particle size, serum creatinine, and fibrinogen. Additional study procedures include measurements of weight and height, waist and hip girth, and brachial and ankle blood pressures. Electrocardiography will also be performed. A questionnaire will be administered Participants will subsequently be interviewed yearly and clinical and hospital records and death certificates will be collected to document new cardiovascular disease events. Findings regarding the prevalence and incidence of cardiovascular disease and associated risk factors will be of great public health importance in directing further at preventing these conditions in people with Type 1 diabetes of long duration.